Pulsed field magnetization in rare-earth kagome systems. (6th January 2016)

• Record Type: Journal Article
• Authors: Hoch, M J R; Zhou, H D; Mun, E; Harrison, N
• Is Part Of: Journal of physics. Volume 28:Number 4(2016)
• Publication Date: 2016-01-06
• Subjects: kagome -- rare earth -- pulsed field -- magnetization; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/0953-8984/28/4/046001
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: The rare-earth kagome systems R 3 Ga5 SiO14 ( R = Nd or Pr) exhibit cooperative paramagnetism at low temperatures. Evidence for correlated spin clusters in these weakly frustrated systems has previously been obtained from neutron scattering and from ESR and NMR results. The present pulsed field (0–60 T, 25 ms) magnetization measurements made on single crystals of Nd3 Ga5 SiO14 (NGS) and Pr3 Ga5 SiO14 (PGS) at temperatures down to 450 mK have revealed striking differences in the magnetic responses of the two materials. For NGS the magnetization shows a low field plateau, saturation in high transient fields, and significant hysteresis while the PGS magnetization does not saturate in transient fields up to 60 T and shows no hysteresis or plateaus. Nd 3+ is a Kramers ion while Pr 3+ is a non-Kramers ion and the crystal field effects are quite different in the two systems. For the conditions used in the experiments the magnetization behavior is not in agreement with Heisenberg model predictions for kagome systems in which easy-axis anisotropy is much larger than the exchange coupling. The extremely slow spin dynamics found below 4 K in NGS is, however, consistent with the model for Kramers ions and provides a basis for explaining the pulsed field magnetization features.